A 50-year-old steel bridge in Himachal Pradesh's Sirmaur collapsed on Monday when a heavily loaded truck carrying limestone passed through it, leaving the driver injured. Traffic at Sangrah-Haripurdhar and Dadahu-Renukaji was diverted. Locals said the bridge, built with a capacity of 10 tonnes, had weakened due to the weight of trucks, which often carried up to 40 tonnes of limestone.